TireSizesFinder

235/55R20 vs 295/45R20

295/45R20 is 0.28 in (7.0 mm) taller than 235/55R20, a +0.91% diameter difference. With the speedometer set for 235/55R20, an indicated 60 mph is 60.5 mph on 295/45R20.

Is this a safe swap?

Diameter difference +0.91%: under 1%

By overall diameter alone, 295/45R20 is a near match for 235/55R20; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 235/55R20 (30.18 in) vs 295/45R20 (30.45 in)235/55R2030.18 in × 9.25 in295/45R2030.45 in × 11.61 in
Side profile and tread width, drawn to the same scale.
235/55R20 vs 295/45R20 differences
Measurement235/55R20295/45R20Difference% diff
Overall diameter30.18 in (766.5 mm)30.45 in (773.5 mm)+0.28 in (+7.0 mm)+0.91%
Sidewall height5.09 in (129.3 mm)5.23 in (132.8 mm)+0.14 in (+3.5 mm)+2.71%
Section width9.25 in (235.0 mm)11.61 in (295.0 mm)+2.36 in (+60.0 mm)+25.53%
Circumference94.80 in (2,408.0 mm)95.67 in (2,430.0 mm)+0.87 in (+22.0 mm)+0.91%
Revolutions per mile668662−6−0.90%
True speed with the speedometer calibrated for 235/55R20
IndicatedActual on 235/55R20Actual on 295/45R20Difference
30 mph30.0 mph30.3 mph+0.3 mph
60 mph60.0 mph60.5 mph+0.5 mph
75 mph75.0 mph75.7 mph+0.7 mph

Ride-height change: 295/45R20 raises the vehicle by 0.14 in (3.5 mm) at the axle (half the +7.0 mm diameter difference).

295/45R20 is 0.28 in taller than 235/55R20 and 60 mm wider, a 0.91% difference in overall diameter.

With the speedometer calibrated for 235/55R20, an indicated 60 mph is actually 60.5 mph on 295/45R20, and revolutions per mile change from 668 to 662.

Both sizes mount on 20-inch wheels.

Size pages

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Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.